Electrochemical Hydrogen Storage Materials: State-of-the-Art and Future Perspectives

TLDR

Hydrogen, the highest‑energy‑density carrier, requires efficient storage to enable renewable energy, and electrochemical methods offer mild‑condition solutions, yet optimal materials meeting DOE targets remain unclear. This review aims to outline strategies for designing new electrochemical hydrogen‑storage materials and to highlight challenges, gaps, and future directions. The authors survey hydrogen preparation, storage, and the electrochemical performance of alloys, metal compounds, carbonaceous materials, metal oxides, mixed oxides, MOFs, MXenes, and polymers. Mixed‑metal oxides show the best discharge capacity and cycling stability, and the review stresses that future materials should combine large surface area, active conductivity, and low cost to achieve high capacity, safety, and cycle life.

Abstract

Hydrogen is the energy carrier with the highest energy density and is critical to the development of renewable energy. Efficient hydrogen storage is essential to realize the transition to renewable energy sources. Electrochemical hydrogen storage technology has a promising application due to its mild hydrogen storage conditions. However, research on the most efficient electrochemical hydrogen storage materials that satisfy the goals of the U.S. Department of Energy remain open questions. All of the above require strategies for designing new hydrogen storage materials. This review provides a brief overview of hydrogen preparation, hydrogen storage, and details the development of electrochemical hydrogen storage materials. We summarize the electrochemical hydrogen storage capabilities of alloys and metal compounds, carbonaceous materials, metal oxides, mixed metal oxides, metal–organic frameworks, MXenes, and polymer-based materials. It was observed that mixed metal oxides exhibit superior discharge capacity and cycling stability. The review indicates that it is vital to create novel materials with large surface area, active-conductive profiles, and low cost. We describe the challenges, gaps, and future perspectives of electrochemical hydrogen storage materials, and hope that the review could draw more attention to the development of electrochemical hydrogen storage materials with high hydrogen storage capacity, high safety, high cycle stability, and low cost and promoting their practical applications.